Method for forming grooves in abrasive wheels



A. BLOCK Jan. 7, 1958 METHOD FOR FORMING GROOVES IN ABRASIVE WHEELSFi1ed-Sept. 20, 1956 FIG. 3

INVENTOR 4 ALECK BLOCK ATTORNEY United States Patent .0

METHOD FOR FORMING GROOVES IN ABRASIVE WHEELS Aleck Block, Culver City,Calif.

Application September 20, 1956, Serial No. 610,936

6 Claims. (Cl. 51-281) This invention relates to a method for forminggrooves in abrasive wheels.

It is an object of my invention to provide an improved method forforming grooves in abrasive wheels, particularly those of the typecomprising a plurality of leaves having their inner ends secured to acentral core, with a groove being formed in each side of the wheelconcentric with the core, such groove being adapted to receive a ring,flange or other reinforcing member to prevent separation of the leavesfrom the core.

It has been found that previous methods of forming such grooves are notcompletely satisfactory. If a groove is formed in each individual leaf,there is difliculty in aligning the leaves properly to form a smooth andcontinuous circular groove. If a groove is cut in the side of the wheelafter the wheel is formed, it is both expensive and time-consuming,because the abrasive material on the leaves quickly dulls the die orcutting tool and it must be frequently replaced. While burning thegroove avoids these difficulties, it is sometimes dilficult tocompletely control the burning in order to obtain precisely the properdepth or width of groove which is desired. This is particularlyimportant if a ring or flange is to assume a precise position within thegroove.

It is an object of my invention to provide a method which overcomes allof these difficulties.

In essence, my invention contemplates forming an annular groove in anabrasive wheel by applying to the side of the Wheel a cylindrical memberhaving a relatively thin but dull circular open end. The cylindricalmember is suitably attached to a source of rotation and caused to rotateat a substantially high speed. When the open end of the cylindricalmember is brought into contact with the abrasive leaves of the grindingwheel, it becomes hot, particularly along its outer edge, andsimultaneously burns and grinds a groove in the side of the wheel.

Since the edge of the cylindrical member is not sharp, there is nothingwhich becomes dull or worn or which must be replaced. My method thusprovides the advantages of cutting and the advantages of burning, withthe r disadvantages of neither.

It is accordingly an object of my invention to provide a method forforming grooves in abrasive wheels having the advantages and benefits ofthe structure and method set forth above. My invention also comprisessuch other objects, advantages and capabilities as will later more fullyappear and which are inherently possessed by my invention.

While I have shown in the accompanying drawingsa preferred embodiment ofmy invention, it should be and change without departing from the spiritof my invention.

Referring to the drawings:

Fig. 1 is a front elevational view showing the cylindrical member inposition above an abrasive grinding Wheel, with the wheel shown insection;

[as understood that the same is susceptible of modification.

2,818,697 Patented Jan. 7, 1958 ice Fig. 2 is a similar view with theopen end of the cylindrical member broken away and shown partly insection within the groove formed in the wheel;

Fig. 3 is a sectional view of an abrasive grinding wheel with a grooveformed in each side thereof;

Fig. 4 is a top plan view of a portion of the wheel after formation ofthe groove;

Fig. 5 is an enlarged plan view of the area surrounding the groove.

A preferred embodiment which has been selected to illustrate myinvention comprises an abrasive wheel '10 which is formed of a pluralityof leaves 11, the inner ends of which are adhered or otherwise securedto a central circular core 12. At least some of the leaves 11 carrysuitable abrasive material.

In order to form a groove in the side of the wheel 10, I provide acylindrical member 13', having a shaft 14 which is adapted to beconnected to a chuck 15 or other suitable source of comparatively highspeed rotation. The cylindrical member 13 is provided with an open endhaving a circular wall 16, the edge of which is not necessarilysharpened or pointed. The thickness of the wall 16 is substantially thesame or somewhat less than that of the groove being formed.

The cylindrical member 13 is mounted above the wheel 10, which may beheld in place by any suitable holding means such as indicated in dottedlines in Figs. 1 and 2 of the drawings. The cylindrical member 13 isrotated at a comparatively high speed and then brought downwardly untilthe circular wall 16 contacts the edges of the leaves 11 forming thewheel 10.

While the speed of rotation of the cylindrical member 13 may vary withina considerable range, a'speed of approximately 3000 surface feet perminute has been found in practice to produce satisfactory results.

As the wall 16 engages the leaves 11, it encounters a substantial amountof frictional resistance from the abrasive material carried by theleaves as well as from the materials forming the leaves themselves. Thiscauses the wall 16 to become heated to a sufficiently high temperatureso that it partly burns the edges of the leaves 11 in addition tocutting them. The burning is evidenced by smoke which rises from thewheel during the grooving operation and by a searing type ofdiscoloration which is evident around the groove after it has beenformed, as indicated in Fig. 5 of the drawings. Due to the rotation ofthe cylindrical member 13, the portions of the leaves 11 directlyadjacent to the groove are slightly curved in the direction of rotationof the cylindrical member 13.

Application of the cylindrical member 13 to the wheel 10 is continueduntil the desired depth of groove 17 has been formed. The depth of thegroove 17 may be easily and accurately controlled. The wheel 10 is thenturned and another groove 17 formed in the opposite side of the wheel10.

While any suitable materials may be used to form the cylindrical member13, it has been found that a piece of spring steel produces satisfactoryresults with the bottom edge of the wall 16 being no thinner than theremainder of the wall 16.

I claim:

1. The method of forming a circular groove in the side edge of anabrasive wheel having a plurality of abrasive leaves comprising mountinga cylindrical member for high speed rotation adjacent the side of saidwheel, said cylindrical member having an open end with an unsharpenedcircular edge, rotating said cylindrical member at a speed ofapproximately 3000 surface feet per minute with respect to said abrasivewheel, applying the open end of said cylindrical member to the side ofsaid wheel so that the frictional engagement between the abrasive leavesof said wheel and said cylindrical member causes the portion of saidcylindrical member adjacent said open end to become heated, andsimultaneously burning and cutting a groove in the side of said Wheelthrough the heating and rotation of said cylindrical member.

2. The method of forming a circular groove in the side edge of anabrasive wheel having a plurality of abrasive leaves comprising mountinga cylindrical member for high speed rotation adjacent the side of saidwheel, said cylindrical member having an open end with an unsharpenedcircular edge, rotating said cylindrical member at a high speed withrespect to said abrasive Wheel, applying the open end of saidcylindrical member to the side of said wheel so that the frictionalengagement between the abrasive leaves of said wheel and saidcylindrical member causes the portion of said cylindrical memberadjacent said open end to become heated, and simultaneously burning andcutting a groove in the side of said wheel through the heating androtation of said cylindrical member.

3. The method of forming a circular groove in the side edge of anabrasive wheel having a plurality of abrasive leaves comprising mountinga cylindrical member for high speed rotation adjacent the side of saidwheel, said member having an open end with an unsharpened circular edge,rotating said member at a high speed with respect to said abrasivewheel, applying the open end of said member to the side of said wheel sothat the frictional engagement between the abrasive leaves of the saidwheel and said member causes the portion of said member adjacent saidopen end to become heated, and simultaneously burning and cutting agroove in the side of said wheel through the heating and rotation ofsaid member.

I 4. The method of forming a groove in the side of an abrasive wheelhaving a plurality of abrasive leaves comprising mounting a member forhigh speed rotation, said member having an open end with an unsharpenededge, rotating said member at a high speed with respect to said abrasivewheel, applying the open end of said member to the side of said wheel sothat the frictional engagement between the abrasive leaves of said wheeland said member causes the portion of said member adjacent said open endto become heated, and simultaneously burning and cutting a groove in theside of said wheel through the heating and rotation of said member.

5. The method of forming a groove in the side of an abrasive wheelhaving a plurality of abrasive leaves comprising rotating a memberhaving an open end with an unsharpened edge at a high speed with respectto said wheel, applying said edge to the side of said wheel, so that thefrictional engagement between the abrasive leaves of said wheel and saidmember causes the edge of said member to become heated, andsimultaneously burning and cutting a groove in the edge of said wheelthrough the heating and rotation of said member.

6. The method of forming a groove in the side of an abrasive wheelhaving a plurality of abrasive leaves comprising rotating a memberhaving an edge, applying said edge to the side of said wheel so that thefrictional engagement between the abrasive leaves of said wheel and saidmember causes the edge of said member to become heated, andsimultaneously burning and cutting a groove in the edge of said wheelthrough the heating and rotation of said member.

References Cited in the file of this patent UNITED STATES'PATENTS347,949 I MiltimOre Aug. 24, 1886 1,825,277 Lytle Sept. 29, 19312,569,854 Hatcher Oct. 2, 1951 2,749,224 Block June 5, 1956

